In the related art, as a storage device for preventing recorded information from being leaked, a storage device for automatically encrypting recorded data is known. The function of such a storage device is known as a Self Encryption Disk (SED) function. In the storage device including this SED function, an encryption key is generated by a set password and the encrypted data may be decrypted by inputting the password from a host device to the storage device.
In order to protect a storage device connected to a host device from a hot plug attack, a technology of synchronizing timers of both the host device and the storage device and generating common data for authentication of both devices using a timer value for synchronization is known.
However, in the technology of preventing information from being leaked by the SED function, there is a possibility that a password is read from an information flow between the host device and the storage device, there is room for improvement. In the technology of synchronizing the timers of the host device and the storage device, a connection relation between both devices may be verified, but a process or mechanism for synchronizing the timers is necessary in both devices. Thus, a technology of more conveniently improving security of a storage device including a correct connection relation is required.
In the case where encryption is performed without influencing a recording speed, a reading speed, etc. of a storage device in order to prevent information from being leaked, an encryption processing circuit needs to be assembled in the storage device and the storage device becomes complicated. In the device in which the encryption device is assembled, there is regulation in distribution, etc. in many countries, a distribution procedure is cumbersome, and a sale destination is restricted.